The energy efficiency of refrigerator appliances has a large impact on the overall energy consumption of a household. Refrigerators should be as efficient as possible because they are usually operated in a continual fashion. Even a small improvement in the efficiency of a refrigerator appliance can translate into significant annual energy savings for a given household.
Many modern refrigerator appliances possess automatic ice-making capability. Although these ice makers are highly desirable, they have some distinct disadvantages. The automatic ice-making feature, for example, requires more energy-usage than a manual ice-making process (e.g., manual filling of an ice-forming tray and manual ice harvesting). In addition, current automatic ice-forming tray systems are fairly complex, often at the expense of long-term reliability.
More specifically, the harvesting mechanism used by many automatic ice makers is particularly energy-intensive. Like their manual brethren, automatic ice makers usually employ one or more ice-forming trays. Many automatic ice making systems, however, rely on electrical resistance heaters to heat the tray to help release the ice from the tray during an ice-harvesting sequence. These heaters add complexity to the system, potentially reducing the overall system reliability. Just as problematic, the heaters use significant amounts of energy to release ice pieces and cause the refrigerator to expend still further energy to cool the environment that has been heated.